Title
Phylogenetic and biochemical characterization of a novel cluster of intracellular fungal α-amylase enzymes
Author
van der Kaaij, R.M.
Janeček, Š.
van der Maarel, M.J.E.C.
Dijkhuizen, L.
TNO Kwaliteit van Leven
Publication year
2007
Abstract
Currently known fungal α-amylases are well-characterized extracellular enzymes that are classified into glycoside hydrolase subfamily GH13_1. This study describes the identification, and phylogenetic and biochemical analysis of novel intracellular fungal α-amylases. The phylogenetic analysis shows that they cluster in the recently identified subfamily GH135_5 and display very low similarity to fungal α-amylases of family GH13_1. Homologues of these intracellular enzymes are present in the genome sequences of all filamentous fungi studied, including ascomycetes and basidiomycetes. One of the enzymes belonging to this new group, Amy1p from Histoplasma capsulatum, has recently been functionally linked to the formation of cell wall α-glucan. To study the biochemical characteristics of this novel cluster of α-amylases, we overexpressed and purified a homologue from Aspergillus niger, AmyD, and studied its activity product profile with starch and related substrates. AmyD has a relatively low hydrolysing activity on starch (2.2 U mg-1), producing mainly maltotriose. A possible function of these enzymes in relation to cell wall α-glucan synthesis is discussed. © 2007 SGM.
Subject
Nutrition
Food technology
amylase
amylase 1p
amylase D
glucan
maltotriose
starch
article
Ascomycetes
Aspergillus niger
Basidiomycetes
enzyme activity
enzyme analysis
gene cluster
gene overexpression
gene sequence
Histoplasma capsulatum
nonhuman
nucleotide sequence
phylogeny
priority journal
protein purification
sequence homology
alpha-Amylase
Amino Acid Sequence
Animals
Aspergillus niger
Cell Wall
Fungal Proteins
Fungi
Glucans
Histoplasma
Molecular Sequence Data
Phylogeny
Sequence Alignment
Starch
Substrate Specificity
Ajellomyces capsulatus
Ascomycota
Aspergillus niger
Basidiomycota
Fungi
To reference this document use:
http://resolver.tudelft.nl/uuid:114aea67-f33f-4d3c-a4ba-45941eb3fc9d
DOI
https://doi.org/10.1099/mic.0.2007/008607-0
TNO identifier
240324
ISSN
1350-0872
Source
Microbiology, 153 (12), 4003-4015
Document type
article